Foreign minister Laurent Fabius told France-Inter radio that IS is "a monster", adding: "But if all the countries in the world aren't capable of fighting against 30,000 people (IS members), it's incomprehensible."

The group claimed responsibility for Friday's attacks on a rock concert, cafes and France's national stadium that killed at least 129 people.

France has stepped up its air strikes against extremists in Syria since the attack, and President Francois Hollande is going to Washington and Moscow next week to push for a stronger international coalition against IS.

Meanwhile, Belgian prime minister Charles Michel has announced a package of additional anti-terror measures in the wake of the attacks.

Mr Michel said €400m would be earmarked to expand the anti-terror fight

He told legislators in a special announcement that personnel involved in security would be increased, and said special attention would be paid to eradicating messages of hate.